Normally I hate massive code drops, but heh.

The code has been drastically re-arranged.
Instead of populating a custom structure while parsing dhcp messages, we now pluck what we need right out of the message itself. We have custom functions and a lookup table to make this really easy.
This makes us more like dhclient and udhcpc, and will enable us to easily add (and remove!) more dhcp options without having to actually change the code (much).
We now store the real dhcp message we got in /var/db/dhcpcd-$iface.lease, the mtime of the file being used as when we got the lease. This file is read in when re-using an old lease instead of parsing the .info file.
The benefit of all of this means that we're actually ~15k smaller when compiled with the same features.
This has been tested for quite some time, and I'm pretty sure most bugs with the 3.2 branch have been fixed whilst making this. Right now, we are 99% command line compatible with the 3.2 branch.

1 files changed, 30 insertions, 87 deletions

diff --git a/socket.c b/socket.c
index b9862a65..97a24be4 100644
--- a/socket.c
+++ b/socket.c
@@ -26,15 +26,20 @@
 
 #include <sys/types.h>
 #include <sys/ioctl.h>
-#include <sys/param.h>
 #include <sys/socket.h>
-#include <sys/uio.h>
 
 #include <net/if.h>
 #include <netinet/in_systm.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
 
+#ifdef __linux__
+# include <asm/types.h> /* needed for 2.4 kernels for the below header */
+# include <linux/filter.h>
+# include <netpacket/packet.h>
+# define bpf_insn sock_filter
+#endif
+
 #include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
@@ -43,17 +48,10 @@
 #include <time.h>
 #include <unistd.h>
 
-#ifdef __linux__
-# include <asm/types.h> /* needed for 2.4 kernels for the below header */
-# include <linux/filter.h>
-# include <netpacket/packet.h>
-# define bpf_insn sock_filter
-#endif
-
 #include "config.h"
+#include "common.h"
 #include "dhcp.h"
-#include "if.h"
-#include "socket.h"
+#include "net.h"
 #include "bpf-filter.h"
 
 /* A suitably large buffer for all transactions.
@@ -69,10 +67,10 @@ static const uint8_t ipv4_bcast_addr[] = {
 	0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff
 };
 
-
 void
 setup_packet_filters(void)
 {
+#ifdef __linux__
 	/* We need to massage the filters for Linux cooked packets */
 	dhcp_bpf_filter[1].jf = 0; /* skip the IP packet type check */
 	dhcp_bpf_filter[2].k -= ETH_HLEN;
@@ -82,48 +80,18 @@ setup_packet_filters(void)
 
 	arp_bpf_filter[1].jf = 0; /* skip the IP packet type check */
 	arp_bpf_filter[2].k -= ETH_HLEN;
-}
-
-static int open_listen_socket(struct interface *iface)
-{
-	int fd;
-	union sockunion {
-		struct sockaddr sa;
-		struct sockaddr_in sin;
-	} su;
-	struct ifreq ifr;
-	int n = 1;
-
-	if ((fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1)
-		return -1;
-
-	memset(&su, 0, sizeof(su));
-	su.sin.sin_family = AF_INET;
-	su.sin.sin_port = htons(DHCP_CLIENT_PORT);
-	if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &n, sizeof(n)) == -1)
-		goto eexit;
-	if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &n, sizeof(n)) == -1)
-		goto eexit;
-	memset(&ifr, 0, sizeof(ifr));
-	strncpy(ifr.ifr_name, iface->name, sizeof(ifr.ifr_name));
-	if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr)) == -1)
-		goto eexit;
-	if (bind(fd, &su.sa, sizeof(su)) == -1)
-		goto eexit;
-
-	iface->listen_fd = fd;
-	close_on_exec(fd);
-	return 0;
 
-eexit:
-	close(fd);
-	return -1;
+	/* Some buggy Linux kernels do not work with ~0U.
+	 * 65536 should be enough for anyone ;) */
+	dhcp_bpf_filter[9].k = 65536;
+	arp_bpf_filter[5].k = 65536;
+#endif
 }
 
 int
 open_socket(struct interface *iface, int protocol)
 {
-	int fd;
+	int s;
 	union sockunion {
 		struct sockaddr sa;
 		struct sockaddr_in sin;
@@ -132,18 +100,10 @@ open_socket(struct interface *iface, int protocol)
 	} su;
 	struct sock_fprog pf;
 
-	/* We need to bind to a port, otherwise Linux generate ICMP messages
-	 * that cannot contect the port when we have an address.
-	 * We don't actually use this fd at all, instead using our packet
-	 * filter socket. */
-	if (iface->listen_fd == -1 && protocol == ETHERTYPE_IP)
-		if (open_listen_socket(iface) == -1)
-			return -1;
-
-	if ((fd = socket(PF_PACKET, SOCK_DGRAM, htons(protocol))) == -1)
+	if ((s = socket(PF_PACKET, SOCK_DGRAM, htons(protocol))) == -1)
 		return -1;
 	
-	close_on_exec(fd);
+	close_on_exec(s);
 	memset(&su, 0, sizeof(su));
 	su.sll.sll_family = PF_PACKET;
 	su.sll.sll_protocol = htons(protocol);
@@ -161,28 +121,28 @@ open_socket(struct interface *iface, int protocol)
 		pf.filter = dhcp_bpf_filter;
 		pf.len = sizeof(dhcp_bpf_filter) / sizeof(dhcp_bpf_filter[0]);
 	}
-	if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &pf, sizeof(pf)) != 0)
+	if (setsockopt(s, SOL_SOCKET, SO_ATTACH_FILTER, &pf, sizeof(pf)) != 0)
 		goto eexit;
 
-	if (bind(fd, &su.sa, sizeof(su)) == -1)
+	if (bind(s, &su.sa, sizeof(su)) == -1)
 		goto eexit;
 
 	if (iface->fd > -1)
 		close(iface->fd);
-	iface->fd = fd;
+	iface->fd = s;
 	iface->socket_protocol = protocol;
 	iface->buffer_length = BUFFER_LENGTH;
 
-	return fd;
+	return s;
 
 eexit:
-	close(fd);
+	close(s);
 	return -1;
 }
 
 ssize_t
 send_packet(const struct interface *iface, int type,
-	    const unsigned char *data, ssize_t len)
+	    const uint8_t *data, ssize_t len)
 {
 	union sockunion {
 		struct sockaddr sa;
@@ -213,16 +173,12 @@ send_packet(const struct interface *iface, int type,
 /* Linux has no need for the buffer as we can read as much as we want.
  * We only have the buffer listed to keep the same API. */
 ssize_t
-get_packet(const struct interface *iface, unsigned char *data,
-	   unsigned char *buffer, ssize_t *buffer_len, ssize_t *buffer_pos)
+get_packet(const struct interface *iface, uint8_t *data,
+	   uint8_t *buffer, ssize_t *buffer_len, ssize_t *buffer_pos)
 {
 	ssize_t bytes;
-	union
-	{
-		unsigned char *buffer;
-		struct udp_dhcp_packet *packet;
-	} pay;
 	struct timespec ts;
+	const uint8_t *p;
 
 	/* We don't use the given buffer, but we need to rewind the position */
 	*buffer_pos = 0;
@@ -244,23 +200,10 @@ get_packet(const struct interface *iface, unsigned char *data,
 		return bytes;
 	}
 
-	if ((unsigned)bytes < (sizeof(pay.packet->ip) +sizeof(pay.packet->udp)))
-	{
-		errno = EBADMSG;
-		return -1;
-	}
-
-	pay.buffer = buffer;
-	if (bytes < ntohs(pay.packet->ip.ip_len)) {
-		errno = EBADMSG;
-		return -1;
-	}
-
-	if (valid_dhcp_packet(buffer) == -1)
+	if (valid_udp_packet(buffer) != 0)
 		return -1;
 
-	bytes = ntohs(pay.packet->ip.ip_len) -
-		(sizeof(pay.packet->ip) + sizeof(pay.packet->udp));
-	memcpy(data, &pay.packet->dhcp, bytes);
+	bytes = get_udp_data(&p, buffer);
+	memcpy(data, p, bytes);
 	return bytes;
 }